In terms of functionality, ‘springs’ can be classified in three categories including compression spring, torsion spring and tension spring, and common compression spring is formed by spirally coiling metal wires with strong elasticity, such as steel wires, and generates elasticity by means of their elastic deformation. Such a compression spring is fixed and nonadjustable in elasticity after being formed and still takes up a large space after being compressed, and satisfactory comfortable level cannot be imparted to all the application areas when it is used for spring mattress and the like. Gas spring has been designed, but it consists of a cylinder, a piston (push rod), an additional built-in spring and other parts, which leads to complex structure and high requirement on inter-part fitting; furthermore, the gas spring above is insufficient in deformation stroke and small in hardness adjustment range, and stills takes up a large space when not used.